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Interpretation Response #22-0029

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Belshire Environmental Services Inc.

Individual Name: Bear Bridges

Location State: CA Country: US

View the Interpretation Document

Response text:

December 22, 2022

Mr. Bear Bridges
Belshire Environmental Services Inc.
25971 Towne Centre Drive
Foothill Ranch, CA 92610

Reference No. 22-0029

Dear Mr. Bridges:

This letter is in response to your March 23, 2022, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to Class 7 (radioactive) materials. Specifically, you pose several questions pertaining to scenarios in which natural materials and ore are not subject to subpart I of Part 173 of the HMR and request clarification on how to properly calculate the exempt activity concentration for mixtures of nuclides.

We have paraphrased and answered your questions as follows:

Q1. You ask whether natural materials—which have been processed for purposes other than the extraction of radionuclides—can utilize the 10 times exempt material activity concentration values referenced in § 173.401(b)(4). You provide captured drilling mud or fluids from the installation of monitoring, remediation, or water wells as examples of such natural materials.

A1. As provided in § 173.401(b)(4), natural materials and ores containing naturally occurring radionuclides which are either in their natural state or which have only been processed for purposes other than for extraction of the radionuclides—and which are not intended to be processed for the use of these radionuclides—are exempt from subpart I of Part 173 of the HMR, provided the activity concentration of the material does not exceed 10 times the exempt material activity concentration values specified in § 173.436, or determined in accordance with the requirements of § 173.433. However, the examples you provided do not meet these requirements as the radionuclides would not be contained in natural materials or ores.

Q2. You ask whether § 173.401(b)(4) would apply to residues that have been extracted or generated from other processing of natural materials such as groundwater treatment systems.

A2. Section 173.401(b)(4) applies to residues that have been extracted or generated from other processing of natural materials, but not when those residues have been transferred to other media such as groundwater treatment systems.

Q3. You ask whether it is appropriate to apply the 10 times exempt material activity concentration values to filtration media that is unintentionally capturing naturally occurring radionuclides—such as filter media that is designed to treat an organic or metal contamination—and is inadvertently capturing radionuclides.

A3. The answer is no. Section 173.401(b)(4) does not apply to radionuclides that have been filtered out intentionally or unintentionally as the material has been transferred to media other than natural materials or ores.

Q4. You ask whether it is appropriate to apply the 10 times exempt material activity concentration values to filtration media in water treatment systems that have stages or processes explicitly designed to capture radionuclides for the purpose of removing them to meet drinking, wastewater, or other standards.

A4. See answer A3.

Q5. You ask when determining the exempt activity concentration for mixtures of nuclides provided in § 173.433(d)(6) and/or the exempt consignment activity limit for mixtures of nuclides provided in § 173.433(d)(7), whether the variable "f(i)" is intended to be the fraction of activity attributable to a specific nuclide "i" divided by the total activity of all nuclides in the mixture, or the activity of a single nuclide in the mixture.

A5. The variable "f(i)" in the formula provided in § 173.433(d)(6) is intended to be the fraction of activity concentration of a specific nuclide in the mixture divided by the total activity of all nuclides in the mixture, while "f(i)" in the formula provided in § 173.433(d)(7) is intended to be the fraction of activity of a specific nuclide in the mixture divided by the total activity of all nuclides in the mixture

Q6. You ask whether the example you provided in your email—of a calculation utilizing the formula in § 173.433(d)(6)—is accurate.

A6. The answer is yes.

I hope this information is helpful. Please contact us if we can be of further assistance.

Sincerely,

T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

173.401(b)(4), 173.433, 173.433(d)(6), 173.433(d)(7), 173.436

Regulation Sections

Section Subject
173.401 Scope
173.433 Requirements for determining basic radionuclide values, and for the listing of radionuclides on shipping papers and labels
173.436 Exempt material activity concentrations and exempt consignment activity limits for radionuclides